BUREAU OF CHEMISTRY. 441 



THE INFLUENCE OP TIN RECEPTACLES ON THEIR CONTENTS. 



This study has been continued during the past year. A set of 

 samples of 11 varieties of foods packed in lacquered containers of 

 heavy and light coating were examined for the second time after 

 the interval of a year, to note the increase of tin content on storage. 

 Samj)les of 22 additional varieties of foods were examined 6 months 

 after canning, in order to determine the amount of tin contained in 

 the foods at the earliest date at which they are likely to reach the 

 consumer. Additional samples of these goods are retained for future 

 examination. The results thus far obtained indicate that some of the 

 acid fruits when packed in plain tin contain from 200 to 250 mg of tin 

 per kilogram of material, exclusive of juice, at the earliest date on 

 which they are likely to reach the consumer, and that tliis amount is 

 greatly increased after a year's additional storage. The amount of 

 tin dissolved by the food is greatly decreased by the use of lacquered 

 tin. 



Special attention has been given to the question as related to a 

 number of foods which are practically free from acid, but which are 

 known to attack tin to a considerable extent, such as canned shrimp, 

 pumpkin, and string beans. Since this action was most pronounced 

 with shrimps, they were first studied, and it appeared that the action 

 in such cases is due to the presence of volatile alkalies, inasmuch as 

 mono-methyl-amin was found in considerable quantities in canned 

 shrimps and amins and amino acids are present in the foods men- 

 tioned. 



EDIBLE OILS. 



In collaboration with the Bureau of Plant Industry, progress has 

 been made in the clarification of peanut oil, and a study has been in- 

 augurated of the chemical composition of various soft-shelled pecans 

 and of the oil contained by them, with a view to determining whether 

 the composition would shed any light on the distinguishing features 

 of various varieties. 



WORMY AND DECOMPOSED FOODS. 



Certain classes of dried fruits in a wormy and partially decayed 

 condition continue to be placed on the market. This results from 

 several causes — sometimes from curing by imperfect methods and in 

 insanitary surroundings, and sometimes from careless storage, the 

 products being exposed unduly to the attacks of insects. In ripe 

 olives decay has sometimes resulted from the practice of discarding 

 the brine in which they were originally packed, for the purpose of 

 saving freight. In such cases, especially when shipments are exposed 

 to unusual delay, the goods reached tliis country in a condition that 

 did not warrant their use as food. The risk involved in this method 

 of shipment has been pointed out. 



It has frequently liappened also that a considerable portion of the 

 ripe olives shipped in bulk were contaminated by worms. Figs and 

 marrons, imported into the country to a considerable extent in the 

 fall, were frequently found to be wormy and sometimes moldy and 

 decayed. The efforts of the department in this direction have 



